Things to check when not starting

I’m having trouble starting Tribler. The main window is not shown but Tribler is in the task bar. A log is produced when Tribler is closed.

Tribler Core and GUI are two different processes and sometimes there could be the core process running if Tribler fails to shutdown correctly. If you restart Tribler, it will kill any previous Tribler processes before it starts.

From the log, it seems Tribler is shutting down immediately after it tries to start but there is not much information to know what went wrong.
Tribler uses port 8085 to communicate with the Core, do you have any idea if it is used by some other process or blocked by firewall perhaps?
Could you check the output of this URL at your browser after starting Tribler?
http://localhost:8085/state